On March 20, the Grand Finale of the YouTube Symphony Orchestra 2011 was held at Sydney Opera House and live-streamed to the world on YouTube During the week-long festival leading up to the finale, 101 musicians from 33 countries joined together for the first time—immersed in new cultural experiences, musical mentorship and performances in one of the world’s most iconic symbols of the arts.

During the three-and-a-half hour Grand Finale—and as people in different timezones awoke to re-broadcasts—the event was streamed 33 million times around the world to 189 countries. This included 2.8 million mobile live-streams—making it one of our biggest ever streaming events to date, on mobile and desktop. That means the event was streamed to nearly one-and-a-half times the entire population of Australia, where the event took place.

One of the goals of the YouTube Symphony Orchestra is to make classical music accessible; the total data transferred by the stream was a whopping 422 terabytes—the equivalent of 145 million MP3 files of classical music being emailed around the world.

Enormous thanks go to all our Symphony members who flew to Sydney from around the world and put their hearts and souls into an extraordinary performance. You surprised and moved people and had some fun along the way!

For the rest of you, you can read about the experience of YouTube Symphony Orchestra 2011 cellist Mathisha Panagoda in a guest post on the YouTube Australia blog. And if you missed the Grand Finale, you can watch the full concert and highlights from the last week anytime at youtube.com/symphony.